NAME

nmdm -- nullmodem terminal driver

SYNOPSIS

devicenmdm

DESCRIPTION

The nmdm driver provides two tty(4) devices connected by a virtual ``null
modem'' cable.
If either of the two tty devices have the CDSR_OFLOW bit (``stty
dsrflow'') set in their line discipline, the nmdm device will emulate the
speed configured in the termios(4) settings. The speed emulation works
independently in the two directions, controlled by the slower end's
termios settings (c_ispeed, c_ospeed, CS5 ... CS8, CSTOPB and PARENB).

FILES

/dev/nmdmN[AB] nullmodem device nodes. Where the A node has a matching
B node.
The nmdm driver implements ``on-demand device creation'' so simply
accessing a given instance in /dev will create it.